I usually do 100 min boil (90 min plus 10 min pre-boil before I add bittering hops). This time is best for most beers, 60 minutes is often not enough to dive-off DMS and other unwanted flavours, especially when you use lots of pilsner malt and you have no posibility to cool the wort down quickly.
But long-time boils have also some disadvantages: wort darkening, kettle camelization, excessive melanoidin formation, so when you make a delicate beer, don't boil too long and don't use too big flame.